As top-secret, super-fast missile experiments go, it wasn’t the most successful. This week the US tested its Advanced Hypersonic Weapons system, the Pentagon’s latest attempt to create a weapon that can reach any target in the world, in just an hour. Instead it exploded within four seconds of takeoff and fell back down to earth, causing undisclosed damage to the test site.

Yet while the system failed this test, it’s unlikely to cool the enthusiasm for developing such a weapon – which has already sparked a new arms race between China, Russia and the US – and which critics fear could potentially spark a nuclear war.

The need for faster conventional weapons was underlined for the US back in 1998. Osama bin Laden had been spotted in a terrorist training camp in the east of Afghanistan, but when missiles – capable of travelling at 880kph – were dispatched to kill him, from a warship in the Arabian sea, the Al-Qaida leader left before he could be hit.

The latest hypersonic prototype, which was tested in Alaska, can only travel 5,000 miles, so it is someway off from the target of reaching anywhere in the world in an hour. But it travels at several times the speed of sound, and can go faster than 3,500 mph. It also has a longer reach than any non-nuclear weapon the US currently possesses.

All the initiatives are cloaked in secrecy, with little public scrutiny of the programme in the US, and no scrutiny at all in Russia or China. Even more worrying is the fact that experts say the hypersonic weapons could be confused for a nuclear attack, sparking a nuclear war. Currently, the Advanced Hypersonic Weapons system is being tested on ballistic missiles, which can also carry nuclear war heads. The way they are launched also looks similar to the way nuclear warheads are launched – but once they leave the atmosphere, they quickly re-enter to glide along 60 miles above the ground, rather than continuing above the atmosphere.

The initial similarities, however, could be enough to frighten countries into retaliating.

And even if this never happens, the prospect of the new weapons is already heating up the debate around nuclear weapons. Foreign Policy magazine reports that the anxieties around the US’s new conventional weapons have led to internal discussions in China over whether it should abandon its policy not to use nuclear weapons first. And Russia is said to be no longer interested in reducing its nuclear capabilities for the same reason.

On this evidence, it may be best for all of us if the prototypes keep exploding when they’re not supposed to.